Scalable video transmission is used to adjust the rate of video depending on the level of network congestion. Previous studies on scalable video transmission of MPEG over ATM ABR service required major changes in the network protocols, and did not provide methods to determine the ABR connection parameters. In this paper, we propose a new scalable video transmission scheme which does not require major changes in network protocols. In our proposed scheme, frames are dynamically dropped either by the source or the network depending on the level of network congestion.